The present invention is related to an earth stratum flush monitoring method and a system thereof. Multiple transmitter units are embedded in the earth stratum at different predetermined locations. When the earth stratum is flushed, the respective transmitter units will buoy and displace to emit different signals. A signal receiving apparatus receives the signals to monitor and know the real-time flush depth and displacement of the earth stratum.
In a steep maintain district, when encountering a downpour, a flood often flushes the earth stratum to form Debris-flow which will result in damage of constructions and overflow in a depressed area. The Debris-flow will also damage transportation systems and bridges.
When designing a bridge, the depth of the basis of the foundations (piers or caissons) is determined in consideration of many factors including the change of the river gullet as well as the properties of the river. A bridge flush monitoring system is mainly used to real-time reflect the embedded depth of the foundations for judging the safety of the bridge.
The existent bridge foundation flush monitoring systems are of two types, that is, surface type and embedded type.
With respect to the surface type, some shortcomings exist as follows:
1. When mounting the monitoring sensors and necessary conduit systems to a bridge, the up-stream side of the piers and bridge foundations needs to be extensively excavated to expose the surface of the caisson or piles up to their total depth. It is therefore impractical to mount the monitoring sensors when working on either a constructing bridge or an existing bridge.
2. Mud, rock and alien objects transported by Debris-flow will exert a great impact onto the exposed monitoring sensors and conduits (containing therein power supply) and damage the monitoring system. Under such circumstance, the monitoring function will be lost. This may happen anytime during the history of a Debris-flow. Therefore, the measured maximum flush depth data may be interrupted and naturally is hardly reliable. More importantly, in case any damage takes place, it is necessary to excavate the earth and to restore the entire monitoring system again. It is expensive, time consuming, and laborious task.
With respect to the embedded type, some shortcomings exist as follows:
1. When mounted, it is necessary to drill holes on the cover plate of the foundation (usually made of substantially reinforced concrete) and it is very difficult.
2. The mechanical structures are subjected to difficult operation or failure or damage due to wear, misplacement and deformation of gear or chain.
3. Still a part of the pipeline and mechanical equipment must be embedded in one side of the foundation. The conduits and mechanical equipments are subject to impact of the flood. In addition, one side of the bridge foundation still needs to be extensively excavated.
Consequently, a new monitoring system is required to provide safe and reliable real-time earth stratum flush data at reasonable cost. Moreover, it should be easy to be placed anywhere in the river gullet. The monitoring system needs to be anti-impact and free from environmental condition during installation.
It is therefore a primary object of the present invention to provide an earth stratum flush monitoring method and a system thereof. Multiple transmitter units are embedded in the earth stratum at predetermined depths. When the earth stratum is flushed, the respective transmitter units will be one by one flushed and displaced and shocked or rotated in accordance with the change of flush depth of the earth stratum. A shock sensor in each transmitter unit will sense this shock and a series of specially encoded radio signals will be emitted. A computerized signal receiving apparatus placed at an appropriate location receives and decodes the signals so as to monitor and report the real-time flush depths of different locations of the earth stratum.
It is a further object of the present invention to provide the above earth stratum flush monitoring method and a system thereof in which the detected real-time flush depth is then transmitted to an early warning unit for the early warning unit to read and judge and emit an alarm in time.
The present invention can be best understood through the following description and accompanying drawings wherein: